Clinical Overview
Atomoxetine is a selective norepinephrine reuptake inhibitor indicated for Attention Deficit Hyperactivity Disorder (ADHD) in children, adolescents, and adults. As a non-stimulant medication, it provides an alternative for patients who cannot tolerate stimulants, have substance abuse concerns, or require 24-hour symptom control.
Primary Clinical Applications
Atomoxetine is indicated for ADHD across all age groups and is particularly valuable for patients with comorbid anxiety, tics, or substance abuse history where stimulants may be contraindicated. It provides consistent symptom control throughout the day and may be preferred when appetite suppression or sleep problems are concerns.
Mechanism and Clinical Benefits
Atomoxetine selectively inhibits the norepinephrine transporter, increasing norepinephrine levels in the prefrontal cortex where this neurotransmitter is crucial for attention and executive function. Unlike stimulants, it has no abuse potential and provides sustained therapeutic effects without rebound symptoms.
Clinical Considerations
Atomoxetine has a delayed onset of action (2-4 weeks for full effect) compared to stimulants and requires daily dosing even on weekends and holidays. It may cause initial nausea and has rare but serious risks of hepatotoxicity and suicidal ideation that require monitoring.
Prescribing Information
Dosing & Administration
ADHD – Children and Adolescents (≤70 kg):
- Initial: 0.5 mg/kg/day for minimum 3 days
- Target: 1.2 mg/kg/day (may give as single dose or divided)
- Maximum: 1.4 mg/kg/day or 100 mg daily, whichever is less
ADHD – Children/Adolescents (>70 kg) and Adults:
- Initial: 40 mg daily for minimum 3 days
- Target: 80 mg daily (may give as single dose or divided)
- Maximum: 100 mg daily
CYP2D6 Poor Metabolizers:
- Initial: Same as above
- Target: 0.5 mg/kg/day (children ≤70 kg) or 40 mg daily (others)
- Maximum: 0.9 mg/kg/day or 80 mg daily
Administration:
- Take with or without food
- May give as single morning dose or divide into morning and late afternoon/early evening
- Swallow capsules whole
Indications
- Treatment of ADHD in pediatric patients (6+ years) and adults
Contraindications
- Hypersensitivity to atomoxetine or any component
- Use with MAOIs (within 14 days)
- Narrow-angle glaucoma
- Pheochromocytoma or history of pheochromocytoma
Warnings & Precautions
- Boxed Warning: Increased risk of suicidal ideation in children and adolescents
- Severe liver injury: Rare but serious risk, monitor for symptoms
- Suicidal ideation: Monitor mood and behavior, especially early in treatment
- Cardiovascular effects: Monitor blood pressure and heart rate
- Growth suppression: Monitor height and weight in pediatric patients
- Urinary retention: Risk in patients with bladder problems
Drug Interactions
- MAOIs: Contraindicated – risk of hypertensive crisis
- Strong CYP2D6 inhibitors: Reduce atomoxetine dose by 50%
- Pressor agents: Use caution, may enhance cardiovascular effects
- Beta-2 agonists: Monitor for cardiovascular effects
Adverse Reactions
Common (≥5%) – Pediatric:
- Nausea, vomiting, fatigue, decreased appetite
- Dizziness, mood swings, irritability
Common (≥5%) – Adult:
- Dry mouth, nausea, decreased appetite, constipation
- Dizziness, sweating, erectile dysfunction
Serious:
- Severe liver injury, suicidal ideation, cardiovascular events
Special Populations
- CYP2D6 poor metabolizers: Reduce target and maximum doses by ~50%
- Hepatic Impairment: Reduce dose for moderate (50%) and severe (75%) impairment
- Pregnancy: Category C – use only if benefits outweigh risks
- Growth monitoring: Regular height and weight checks in children
Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. Always consult with qualified healthcare professionals before making any treatment decisions. Individual patient circumstances may vary significantly.
